1. Field of the Invention
The present invention is directed to a motor-driven massager, and more particularly to a massager having an applicator driven by a motor at a variable operation speed to apply a massaging action to a user's body.
2. Background of the Invention
Prior massagers are known to include an electric motor for driving an applicator at a variable operation speed so that a user can select a suitable operation speed depending upon the portions of the body intended to be massaged. For example, Japanese Patent non-examined early publication (KOKAI) No. 61-247456 proposes a motor-operated massager which is capable of selecting an optimum operation speed depending upon a particular portion of the body intended to be massaged in order to achieve a comfortable massage action at the optimum operation speed. However, even when an optimum operation speed is selected, the operation speed will inevitably vary with a varying load requirement received by the motor due to ever changing pressing forces at which the applicator is pressed against the user's body. That is, the operation speed will normally decrease with the increase of the load requirement, thereby failing to continue the massaging action at the optimum operation speed selected for the intended portion. To avoid the above insufficiently, it is contemplated to control the operation speed kept constant at the selected speed irrespective of the varying load requirement. However, it is found that such scheme alone would result rather in ineffective massaging, particularly when a high operation speed is selected. That is, when the load is increased beyond a certain level, the continued massaging with the operation speed kept still at the high speed would give unpleasant and unnatural massaging effect to the user. Further, the above scheme poses another problem in that the motor is required to have a high power capability and therefore be bulky in order to afford the high speed operation even at the increased load requirement.